Regulatory Matters - Regulatory Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	$ 6,027	$ 4,381
Regulatory liabilities—current	374	185
Total Regulatory Liabilities	6,401	4,566
Future income tax
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,753	1,984
Unrecognized pension and other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,638	32
Allowance for cost of removal less salvage (i)
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,315	1,199
2022 late payment charge deferral
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	127	0
Net unbilled revenue deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	204	209
Deferred derivative gains - long term
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	145	61
Pension and other postretirement benefit deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	144	102
System benefit charge carrying charge
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	73	70
Net proceeds from sale of property
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	69	103
Sales and use tax refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	37	17
Property tax refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	35	35
BQDM and Demonstration project reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	23	25
Earnings sharing - electric, gas and steam
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	13	13
Energy efficiency portfolio standard unencumbered funds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	5	15
COVID - 19 pandemic uncollectible reconciliation deferral
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	12	0
Workers’ compensation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	11	8
Settlement of prudence proceeding (d)
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	10	6
Settlement of gas proceedings (e)
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	0	12
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	413	490
Deferred derivative gains - short term
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	311	142
Refundable energy costs
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	34	32
Revenue decoupling mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	29	11
CECONY
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	5,481	3,921
Regulatory liabilities—current	308	134
CECONY | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	5,481	3,921
Regulatory liabilities—current	308	134
Total Regulatory Liabilities	5,789	4,055
CECONY | Future income tax | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,616	1,840
CECONY | Unrecognized pension and other postretirement costs | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,536	0
CECONY | Allowance for cost of removal less salvage (i) | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,137	1,033
CECONY | 2022 late payment charge deferral | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	123	0
CECONY | Net unbilled revenue deferrals | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	204	209
CECONY | Deferred derivative gains - long term | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	130	55
CECONY | Pension and other postretirement benefit deferrals | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	98	55
CECONY | System benefit charge carrying charge | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	69	63
CECONY | Net proceeds from sale of property | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	69	103
CECONY | Sales and use tax refunds | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	36	16
CECONY | Property tax refunds | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	35	35
CECONY | BQDM and Demonstration project reconciliations | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	21	22
CECONY | Earnings sharing - electric, gas and steam | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	10	10
CECONY | Energy efficiency portfolio standard unencumbered funds | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	7	19
CECONY | COVID - 19 pandemic uncollectible reconciliation deferral | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	12	0
CECONY | Workers’ compensation | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	11	8
CECONY | Settlement of prudence proceeding (d) | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	10	6
CECONY | Settlement of gas proceedings (e) | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	0	12
CECONY | Other | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	357	435
CECONY | Deferred derivative gains - short term | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	287	132
CECONY | Refundable energy costs | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	0	2
CECONY | Revenue decoupling mechanism | Subsidiaries
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	$ 21	$ 0